The Interior Department sent a draft of those Arctic regulations to the Office of Management and Budget on Friday, marking the launch of an interagency review process that typically spans months. The rule’s arrival at OMB was disclosed online by Sunday evening.

Right now, there are no specific mandates governing Arctic oil development. Federal agencies regulate drilling in the Arctic using the same basic rules that apply generally offshore, whether the target is in the balmy Gulf of Mexico or icy Chukchi. Some critics worry that without Arctic-specific requirements, safeguards voluntarily adopted by Shell Oil Co. in 2012 would not be followed by other oil companies planning to drill in the region.

It is unclear how far the new rules may go. Interior Department officials have suggested the measure is likely to focus closely on drilling in the Arctic — and not on potential development and production activities later on. So while the measure may mandate companies have at the ready oil spill response equipment and the personnel to deploy it, the proposal is widely expected to steer clear of requirements for installing pipelines and other infrastructure in the region.

Regulators have signaled that the rule will largely codify steps took voluntarily, including a possible requirement for a containment system in case of a runaway well. Shell built a specialized, first-of-its-kind containment system for the company’s Arctic operations two years ago, although that equipment did not make it to the waters north of Alaska in time.

If a requirement for similar equipment or containment capability is written into new Arctic mandates, other oil companies that hold oil and gas leases in the region, including ConocoPhillips and Statoil, might have to procure such a device before they could begin drilling.

Other possible mandates include requirements for redundant emergency equipment to control blowouts and close well holes in emergencies. The proposal also could force companies to have a drilling rig ready to bore a relief well during an emergency close by.

When it drilled the first stages of two exploratory wells in the region two years ago, Shell had two rigs working simultaneously. A requirement for an idle drilling rig could boost the cost of drilling operations significantly. Rigs designed for more temperate waters can cost up to a million dollars a day in rental rates, and there are few geared toward Arctic conditions.

Offshore operators also could be forced to harden their fleet of vessels, ensuring they are Polar Class ships capable of working in icy conditions. Although exploratory drilling is confined to the “open-water” season, an emergency late in the drilling operations could require vessels and workers to be on the scene after ice starts encroaching on the area.

The proposed rule, drafted by the Bureau of Safety and Environmental Enforcement, has been deemed “economically significant,” a category that means it will have an annual impact on the economy of $100 million or more — or will have a material adverse effect on the economy, productivity, jobs, or state, local and tribal governments.

Some environmentalists say even minimum standards aren’t sufficient to protect the fragile Arctic ecosystem; they say an oil spill at the top of the globe would be devastating, in part because most cleanup methods are geared toward warmer, calmer waters. And they point to the mishaps Shell experienced two years ago, including air pollution violations and the grounding of its Kulluk drilling unit during a failed tow mission, as evidence that even a well-heeled oil company can’t ensure operations are error-free.

Photo: Jennifer A. Dlouhy

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The drillship Noble Discoverer, boring a well in the Chukchi Sea north of Alaska in 2012. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

The drillship Noble Discoverer, boring a well in the Chukchi Sea north of Alaska in 2012. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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The drillship Noble Discoverer, boring a well in the Chukchi Sea north of Alaska in 2012. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

The drillship Noble Discoverer, boring a well in the Chukchi Sea north of Alaska in 2012. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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The drillship Noble Discoverer, boring a well in the Chukchi Sea north of Alaska in 2012. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

The drillship Noble Discoverer, boring a well in the Chukchi Sea north of Alaska in 2012. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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Donald LeCourt, Shell Alaska's wells HSE team leader, and other workers take a helicopter ride to the Noble Discoverer during a crew change on Oct. 9, 2012. In preparation for the hour-long flights over frigid Arctic waters, crew members must complete helicopter underwater escape training and don one-piece Mustang Survival immersion suits filled with foam for insulation and buoyancy. (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Donald LeCourt, Shell Alaska's wells HSE team leader, and other workers take a helicopter ride to the Noble Discoverer during a crew change on Oct. 9, 2012. In preparation for the hour-long flights over frigid ... more

Photo: Jennifer A. Dlouhy

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Workers step off a helicopter onto the Noble Discoverer during a crew change Oct. 9, 2012. Most Shell employees and some contractors on the vessel generally work three week shifts -- with three-week breaks in between the stints. (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Workers step off a helicopter onto the Noble Discoverer during a crew change Oct. 9, 2012. Most Shell employees and some contractors on the vessel generally work three week shifts -- with three-week breaks in ... more

Photo: Jennifer A. Dlouhy

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Shown here is one of the two cranes on the drillship Noble Discoverer, which Shell is using to search for oil in the Chukchi Sea north of Alaska. The cranes can't be used once the temperature dips below 0 degrees celsius -- a challenge in this chilly, Arctic environment. (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Shown here is one of the two cranes on the drillship Noble Discoverer, which Shell is using to search for oil in the Chukchi Sea north of Alaska. The cranes can't be used once the temperature dips below 0 ... more

Photo: Jennifer A. Dlouhy

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Onboard the Noble Discoverer, workers on the rig floor link up drill pipe. Shell is using the ship and its crew to finish the first half of a well in its Burger prospect in the Chukchi Sea -- with a plan to return next year and drill it to completion. (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Onboard the Noble Discoverer, workers on the rig floor link up drill pipe. Shell is using the ship and its crew to finish the first half of a well in its Burger prospect in the Chukchi Sea -- with a plan to ... more

Photo: Jennifer A. Dlouhy

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Senior Drilling Supervisor Loyd Wallace was overseeing work on the Noble Discoverer when it drilled the first foot of Shell's latest Chukchi Sea well -- the first of its kind in more than two decades. Wallace said it felt like Christmas. "Everybody was excited," Wallace said. "Everybody was taking pictures." (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Senior Drilling Supervisor Loyd Wallace was overseeing work on the Noble Discoverer when it drilled the first foot of Shell's latest Chukchi Sea well -- the first of its kind in more than two decades. Wallace ... more

Photo: Jennifer A. Dlouhy

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Kendall Duncan, assistant rig manager, and driller Sheldon Smith coordinate operations inside the drill shack on the Noble Discoverer. Duncan, who is from Poplarville, Miss., says he is still adjusting to the Arctic climate -- including the patches of ice that appear on the vessel. "It's like waking up in the Twilight Zone," Duncan says. (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Kendall Duncan, assistant rig manager, and driller Sheldon Smith coordinate operations inside the drill shack on the Noble Discoverer. Duncan, who is from Poplarville, Miss., says he is still adjusting to the ... more

The blowout preventer on the Noble Discoverer drillship has two sets of shearing rams meant to cut through drill pipe in case of an emergency. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

The blowout preventer on the Noble Discoverer drillship has two sets of shearing rams meant to cut through drill pipe in case of an emergency. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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A view of the 160-foot-tall derrick on the Noble Discoverer. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

A view of the 160-foot-tall derrick on the Noble Discoverer. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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Casing sits on the Noble Discoverer, ready to be run in the first half of the well Shell is drilling in the Chukchi Sea. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Casing sits on the Noble Discoverer, ready to be run in the first half of the well Shell is drilling in the Chukchi Sea. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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Casing sits on the Noble Discoverer, ready to be run in the first half of the well Shell is drilling in the Chukchi Sea. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Casing sits on the Noble Discoverer, ready to be run in the first half of the well Shell is drilling in the Chukchi Sea. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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Pete Slaiby, the vice president of Shell Alaska, surveys the scene on the drillship Noble Discoverer before leaving the vessel on Oct. 9, 2012. As Shell's top executive in Alaska, Slaiby is overseeing the company's new venture in the Chukchi and Beaufort Seas. (Photo: Jennifer A. Dlouhy / The Houston Chronicle) less

Pete Slaiby, the vice president of Shell Alaska, surveys the scene on the drillship Noble Discoverer before leaving the vessel on Oct. 9, 2012. As Shell's top executive in Alaska, Slaiby is overseeing the ... more

Photo: Jennifer A. Dlouhy

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Waves from the Chukchi Sea lap the coast of Barrow, Alaska, the northernmost city in the United States. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Waves from the Chukchi Sea lap the coast of Barrow, Alaska, the northernmost city in the United States. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

Photo: Jennifer A. Dlouhy

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An aerial view of Barrow, Alaska. With a relatively small footprint of about 22 square miles, the city is home to just over 4,000 residents. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)

An aerial view of Barrow, Alaska. With a relatively small footprint of about 22 square miles, the city is home to just over 4,000 residents. (Photo: Jennifer A. Dlouhy / The Houston Chronicle)